CN109153739B

CN109153739B - Amine functional anionic polymer dispersions and coating compositions thereof

Info

Publication number: CN109153739B
Application number: CN201780027458.8A
Authority: CN
Inventors: S·J·博奥克斯; D·E·P·梅斯塔赫
Original assignee: Onyx Holland Co ltd
Current assignee: Onyx Holland Co ltd
Priority date: 2016-05-02
Filing date: 2017-05-02
Publication date: 2020-12-08
Anticipated expiration: 2037-05-02
Also published as: WO2017191131A1; EP3452519A1; US20190144702A1; EP3452519B1; CN109153739A; US10865323B2; DK3452519T3

Abstract

The present invention relates to products and processes obtainable by a process for preparing an aqueous anionically stabilized polymer dispersion, which process comprises: polymerizing a first emulsion of a first monomer mixture to form a first phase oligomer, the first monomer mixture comprising an acid functional monomer and being substantially free of an amine functional monomer; neutralizing and second emulsion polymerizing a second monomer mixture comprising an amine functional monomer having a sterically hindered secondary or tertiary amine group and substantially free of acid functional monomer in the presence of the first phase emulsion to form a second phase of the amine functional polymer, wherein the two phases are unmixed and separate. The invention further relates to dispersions which further comprise reactive and/or non-reactive co-binders, in particular polyepoxide co-binders, and also to the use of the dispersions for preparing coating compositions and coatings having bleed-out resistance.

Description

Amine functional anionic polymer dispersions and coating compositions thereof

Technical Field

The present invention relates to a process for preparing aqueous dispersions of anionic polymers containing amine and acid functional groups. The invention also relates to a coating composition further comprising a reactive or non-reactive co-binder, in particular a polyepoxy curing agent, as reactive co-binder, and to the use of the coating composition for preparing coatings with bleed-out resistance or antimicrobial properties. The aqueous coating composition of the present invention has quick-drying characteristics and rapidly exhibits good water and chemical resistance when dried. These compositions are useful as one-component or two-component formulations for coatings on wood, metal and other surfaces.

Background

It is difficult to incorporate amine functional ethylenically unsaturated monomers into aqueous polymer dispersions that also contain acid functional ethylenically unsaturated monomers. Even at low concentrations of amine functional monomer at a pH below 7 (which is typically the case with anionic persulfate initiated emulsion polymerization), cationic oligomers or polymeric species can be formed which cause coagulation or flocculation of the anionic emulsion polymer. Therefore, it is difficult to synthesize emulsion polymers comprising alkyl substituted amine functional monomers and acid functional monomers with good stability.

Coating compositions based on aqueous anionic polymer dispersions containing amine and acid functional groups are known in the art. Dispersions of polymers with amine and acid functions, prepared using conventional solution polymerization techniques, and then emulsifying the polymer in water, are described in Brinkman et al (Progress in Organic Coatings,34,1998, pages 21-25) and in WO 02/068551. Reference is made to the combination with an epoxy functional polymer dispersion to produce a crosslinked coating. However, these coating compositions have some disadvantages, since the process followed to synthesize the polymers bearing amino and acid groups is cumbersome and time consuming. In addition, the solvent used for solution polymerization must be removed by vacuum distillation, resulting in waste products and increased costs. Accordingly, there is a need for a process for making aqueous dispersions of amine and acid functional polymers that is easier and more cost effective.

A complete study for the preparation of poly (methyl methacrylate-butyl acrylate) aqueous nanoparticles surface functionalized with amino groups was described by Mahdavian et al (adv. in polymer.tech.276 (2011)). Methods for preparing such dispersions include seeded emulsion and microemulsion polymerization. The latex is said to be film-forming. The concentration of amine and carboxyl groups in the polymer was quite low, 1.8 wt% and 0.03 wt%, respectively.

US 4,760,110 and US 3,404,114 describe a two stage emulsion polymerization process with an intermediate neutralization step which allows for the introduction of higher levels of amino and carboxylic acid functional monomers. However, the amino and acid levels are lower.

EP0794018 describes an aqueous coating composition having a dispersion of an acrylic polymer with acid and amine functional groups, wherein the amine functional groups are in a non-ionic state due to the pH level of such a dispersion. Amine and acid functional polymers are prepared in a single polymerization step and the levels of amine and acid monomers in the polymer are low; the amine monomer content in the examples was not higher than 7 wt% and the acid monomer amount in the examples was not higher than 2 wt%.

Due to the increasing legislative pressure to reduce Volatile Organic Compound (VOC) emissions from coatings, there remains a need for aqueous coating compositions having improved fast drying characteristics and which rapidly yield good water and chemical resistance.

Disclosure of Invention

According to the present invention, there is provided a process for preparing an aqueous anionically stabilized polymer dispersion comprising the steps of:

a. a first emulsion polymerization of a first monomer mixture comprising an acid functional monomer M1 containing acid groups and less than 2 wt% (relative to the total weight of the first monomer mixture), preferably substantially free of an amine functional monomer M2 containing amine groups, to form a first phase polymer dispersion of an acid functional oligomer P1, the acid functional oligomer P1 having a number average molecular weight Mn_P1From 500 to 50000 g/mol, preferably from 1000 to 30000 g/mol (determined by GPC using THF in combination with acetic acid) and the Fox glass transition temperature Tg_P1At least 0, preferably at least 10, 15 or even at least 20 c,

b. adding a base, preferably a volatile base, preferably ammonia, to increase the pH to a range of 6-11, preferably 7.5-11,

c. a second emulsion polymerization of a second monomer mixture comprising an amine-functional monomer M2 having a sterically hindered secondary or tertiary amine group and comprising less than 2 wt% (relative to the total weight of the second monomer mixture), preferably substantially free of acid-functional monomer M1, in the presence of the first phase polymer dispersion to form a polymer having a Fox glass transition temperature Tg_P2A second phase of amine-functional polymer P2 at a temperature of at least 0 ℃,

d. wherein Tg is_P2Specific Tg_P1At least 5 deg.C lower, more preferably at least 7, 10 or 20 deg.C lower, and

e. wherein the resulting anionically stabilized polymer dispersion comprises dispersed particles having separate unmixed first and second phases within the particles, wherein the Fox Tg is calculated based on the constituent monomers in the monomer mixture excluding chain transfer agents or reactive surfactants.

The invention also relates to an aqueous anionically stabilized polymer dispersion obtainable by this process, in particular an aqueous anionically stabilized polymer dispersion comprising dispersed particles having two or more separate phases within the particles, one phase comprising an acid functional oligomer or polymer substantially free of amine functional monomers and another separate phase comprising an amine functional polymer or oligomer substantially free of acid functional monomers, and wherein the amount of amine functional monomers is at least 4 wt% relative to the total weight of the polymers or oligomers in the dispersed particles.

These dispersions are referred to as anionic polymer dispersions and "anionically stabilized" dispersions, meaning that in the liquid state the surfaces of the polymer dispersion particles carry a negative charge, which is balanced by the presence of cations in the liquid phase. The dispersions according to the invention are very suitable for preparing coating compositions for fast drying aqueous coatings, in particular for functional coatings on metal, mineral and wood substrates.

The invention also relates to coating compositions comprising the aqueous anionic polymer dispersions of the invention, with or without co-binders which can be reactive (as two-component coating systems) or non-reactive (as one-component coating systems) with the amine or acid groups of the aqueous anionic polymers.

One preferred embodiment of the present invention is an aqueous two-component coating composition comprising: an anionic aqueous polymer dispersion prepared by emulsion polymerization as a first component, said dispersion comprising a plurality of polymer particles containing at least two different polymer phases P1 and P2, wherein one phase (P1) has pendant acid functional groups and the other phase (P2) has pendant alkyl-substituted amine functional groups, and as a second component, a compound having pendant functional groups that co-react with the acid and/or amine functional groups of the first component, forms a crosslinked polymer network when dried.

In particular, the present invention relates to coating compositions comprising aqueous anionic polymer dispersions blended with aqueous dispersions of polyepoxide reactive co-binders, and their use in coatings providing bleed-out resistance or antimicrobial properties.

The present invention also relates to a method of preparing a fast drying coating having early water and chemical resistance on a suitable substrate comprising: applying a layer of an anionic aqueous polymer dispersion made by emulsion polymerization consisting of a plurality of polymer particles containing at least two different polymer phases, one phase having pendant acid functional groups and the other phase having pendant alkyl substituted amine functional groups.

The first process step is a first emulsion polymerization of a first monomer mixture comprising the acid-functional monomer M1 containing acid groups and less than 2 wt.%, more preferably less than 1 wt.%, even more preferably less than 0.5 wt.% (relative to the total weight of the first monomer mixture) of the amine-functional monomer M2 containing amine groups. It is preferred that the first monomer mixture is substantially free of amine functional monomer M2 containing amine groups, as amine groups can destabilize the dispersion of acid functional oligomer P1. In this step, an emulsion of the acid-functional oligomer P1 of the first phase is formed, the number-average molecular weight Mn of which_P1From 500 to 50000 g/mol, preferably from 1000 to 30000 g/mol (determined by Gel Permeation Chromatography (GPC) using tetrahydrofuran in combination with acetic acid)). Mn considering the viscosity of the oligomer dispersion at a pH higher than 6_P1Should not be too high, and Mn in view of achieving sufficient chemical resistance and water resistance_P1Should not be too low. The glass transition temperature Tg of the acid-functional oligomer, calculated according to the Fox equation, taking into account the envisaged coating properties_P1At least 0 ℃, preferably at least 10, 15 or 20 ℃, but preferably at least 30 ℃ and possibly above 50 ℃. The Fox Tg is calculated based on the constituent monomers in the monomer mixture that do not include a chain transfer agent or a reactive surfactant.

Subsequently a base, preferably a volatile base, is added to increase the pH to a range of 6-11, preferably 7.5-11. In step b, the pH is increased to hydroplasticize the acid functional oligomer and to keep the sterically hindered secondary or tertiary amine group in a deprotonated state during and after the second polymerization step c. By addition of a base such as ammonia; alkali metal hydroxides such as sodium hydroxide or lower alkylamines such as, but not limited to, 2-methylaminoethanol, 2-dimethylethanolamine, N-methylmorpholine, N-diisopropylethylamine, and triethylamine can raise the pH. Preferably a volatile base such as ammonia, or a mixture of a volatile base and a non-volatile base; most preferred is ammonia or 2-dimethylethanolamine.

A second emulsion polymerization occurs in the presence of the first stage polymer dispersion by adding a second monomer mixture comprising an amine functional monomer having a sterically hindered secondary or tertiary amine group and less than 2 wt% (relative to the total weight of the second monomer mixture), preferably substantially free of acid functional monomer, to form a polymer having a Fox glass transition temperature Tg_P2A second phase of amine functional polymer P2 at a temperature of at least 0 ℃.

Number average molecular weight Mn of the amine-functional Polymer P2_P2Can vary within wide limits, typically 1000-. The first stage oligomer P1 generally has a lower molecular weight than the second stage polymer, and Mn_P2Higher than Mn_P1Preferably at least 1000 g/mole, more preferably at least 2000, 4000 or 8000 g/mole. The control of the molecular weight is described in more detail below.

The monomers of the first and second monomer mixtures are selected such that the Tg_P2Below Tg_P1At least 5 ℃, more preferably at least 7, 10 or 20 ℃, but the difference can be at least 25 or even 30 ℃. As explained in more detail below, the Fox Tg herein is calculated based on the constituent monomers in the monomer mixture that does not include a chain transfer agent or a reactive surfactant.

The particle size of the resulting polymer dispersions varies generally between 20 and 1000nm, preferably between 50 and 500nm (Z-average determined by photon correlation spectroscopy). When amine functional anionically stabilized dispersions are used in combination with co-reactive dispersions, it is advantageous that the particle size of the two polymer dispersions is similar.

Number-average and weight-average molecular weights (M) of the oligomeric copolymer P1_nAnd M_w) Can be determined by GPC using a polymer of known molecular weight (e.g. polystyrene) as the standard and tetrahydrofuran or a combination of tetrahydrofuran and acetic acid as the eluent. For polymer P2, M was calculated using a mathematical model represented in the computer program described by c.sayer et al (Computers and Chemical Engineering 25(2001),839)_nAnd M_w。

The Tg of the first phase copolymer and the second phase copolymer was calculated by the Fox equation (t.g.fox, fill.am.phys.soc.1 (1956), 123). The Fox equation, well known in the art, is represented by the following equation: 1/T_g＝W₁/T_g(1)+W₂/T_g(2)+W₃/T_g(3) +.., wherein W is₁、W₂、W₃Etc. are the weight fractions of comonomers (1), (2) and (3) (etc.), and T_g(1)、T_g(2)、T_g(3) The glass transition temperatures (in kelvin) of their respective homopolymers are indicated. In Polymer Handbook, 4 th edition (ed: J.Brandrup, E.H.Immergut, E.A.Grulke, John Wiley&Sons, inc.1999) can be used to make the calculation. T in degrees Kelvin_gCan be easily converted to degrees celsius. The effect of other ingredients of the polymer, such as crosslinking monomers with multiple vinyl groups, chain transfer agents or reactive surfactants, is not taken into account when calculating the Tg from Fox. T is_gThe values were also not corrected for molecular weight effects.

The morphology of the alkyl substituted amine functionalized polymer dispersion particles of the present invention is not intended to be limited in any way, but they need to contain at least two different polymer phases; the polymers are unmixed. The multiphase particles will comprise at least two mutually incompatible copolymer phases P1 and P2 having any of a variety of morphological configurations — for example: core/shell; core/shell particles having a shell phase that does not completely encapsulate the core; a core/shell particle having a plurality of cores, or a core/shell particle, wherein the core consists of two phases or has a gradient composition. In order to make the polymers incompatible with each other, it is required that a certain minimum solubility parameter exists between the polymers P1 and P2A difference. This can be achieved by using Hoy (Hoy KL. "New values of the solubility parameters from the spatial compression data", J.Point Technology,1970,42(541): 76-118) and Van Krevelen/Hoftlayer ("Properties of polymers: the correlation with chemical structure; the numerical estimation and compression from the additional groups distributions", 3^rdedition, Amsterdam: Elsevier; 1990.) calculating solubility parameter of each phase polymer represented by the following formula_TDifference (Δ) of_T) To estimate:_T＝[(_d,p)²+(_p,p)²+(_h,p)]^1/2wherein_d,p、_p,pAnd_h,prespectively Hansen dispersions, polar and hydrogen bond solubility components of the polymer (Hansen et al, "Independent catalysis of the parameter components", j. paint Technology, 1967; 39(511): 511-4). For the calculations, only the polymer components described for the Fox Tg calculation (i.e., based on the constituent monomers in the monomer mixture not including chain transfer agent or reactive surfactant) were also considered. The requirement for having phase separation between the polymers of the present invention is to have_TP1And_TP2a delta which differs by at least 0.1, i.e. at least 0.1 or preferably at least 0.2_T. More preferably a difference Δ of at least 0.3_T。

Experimental techniques for determining the morphology of the separated phases of Polymer dispersion particles, in particular P1 and P2, include electron microscopy (see, for example, Winnik et al, Langmuir, Volume 9, Issue 8, P2053-65 (1993)), dynamic mechanical thermal analysis (Rearick et al, Journal of Coatings Technology, Vol.68, Vol.862, pp.25-31 (1996)) or differential scanning calorimetry (Stubbs et al, Journal of Polymer Science, Part B: Polymer Physics, Vol.43, Vol.19, pp.2790-2806 (2005)).

Preferably in the process of the present invention, the first monomer mixture comprises

a.1 to 20, preferably 2 to 15, more preferably 3 to 10,% by weight of an acid-functional monomer M1,

b. less than 1 wt.%, preferably less than 0.5 wt.% and most preferably no amine-functional monomer M2,

from 80 to 99, preferably from 85 to 98, more preferably from 90 to 97,% by weight of monomers M3 other than acid-functional monomers and amine-functional monomers, and wherein the second monomer mixture comprises

d.2-45 wt%, preferably 3-35 wt% and more preferably 5-30 wt% of an amine functional monomer M2 with a sterically hindered secondary or tertiary amine group,

e. less than 1% by weight, preferably less than 0.5% by weight and most preferably free of acid-functional monomer M1,

from 55 to 98, preferably from 65 to 98, more preferably from 75 or from 78 to 96,% by weight of monomers M3 other than acid-functional monomers and amine-functional monomers,

wherein the wt% is relative to the total weight of the first and second monomer mixtures, respectively, and wherein preferably the amount of M1, M2, and M3 in each mixture adds up to 100 wt%. Preferably, the monomer M3 in c) and f) is a monomer free of ionizable groups and may optionally contain crosslinkable groups other than amine and acid groups. The second monomer mixture does not contain amine functional monomers other than the amine functional monomer M2 having sterically hindered secondary or tertiary amine groups. A large amount of amine functional monomer (e.g. above 25 wt%) in P2 is more difficult in view of dispersion stability, but the amount of amine monomer M2 in P2 is chosen as high as possible in view of bleed resistance, and amounts exceeding 25, 30 or even 35 wt% are desirable and achievable in the process of the invention.

The amount of the second monomer mixture in wt.% relative to the total amount of the first and second monomer mixtures, and thus the amount of polymer P2 relative to the total amount of P1+ P2, is typically 20 to 80 wt.%, more preferably 25 to 70 wt.%. The relative amount of P2 is preferably high in view of providing high amounts of amine groups for the anti-bleed properties, and therefore preferably higher than 30, 40, 50 or even higher than 60 wt%. In view of dispersion stability, 30 to 60 wt% is preferable.

The first phase containing oligomeric copolymer P1 was derived from the emulsion polymerization of acid functional monomer M1, monomer M3 and essentially no amine functional monomer M2 and chain transfer agent for molecular weight control. The second phase contains a copolymer P2 derived from a second monomer mixture comprising an amine functional monomer M2 with sterically hindered secondary or tertiary amine groups, monomer M3 and substantially no acid functional monomer M1. Suitable selections of monomers M1, M2 and M3 in copolymers P1 and P2 are described below. Monomer M3 is preferably a monomer substantially free of ionizable groups and may optionally contain crosslinkable groups other than amine and acid groups. By "substantially free" is meant herein less than 5 wt%, preferably 2 wt%, more preferably less than 1 wt%.

The acid functional vinyl monomer M1 used may be broadly selected from carboxylic acid, phosphonic acid, anhydride, phosphate ester monomers and other functional groups capable of reacting with a base to form a salt. Examples of carboxylic acid functional monomers include (meth) acrylic acid, itaconic acid or anhydride, maleic acid or anhydride, citraconic acid or anhydride, beta-carboxyethyl acrylate, monoalkyl maleates (e.g., monomethyl and monoethyl maleates) and monoalkyl citraconate. In addition to carboxylic acid functional monomers, other acid functional monomers may also be present in the monomer composition, such as, but not limited to, styrenesulfonic acid, vinylbenzylsulfonic acid, vinylsulfonic acid, acryloxyalkylsulfonic acids (e.g., acryloxymethanesulfonic acid), 2-acrylamido-2-alkylalkanesulfonic acids (e.g., 2-acrylamido-2-methylethylsulfonic acid), 2-methacrylamido-2-alkylalkanesulfonic acids (e.g., 2-methacrylamido-2-methylethylsulfonic acid), mono (acryloxyalkyl) phosphates (e.g., mono (acryloxyethyl) phosphate and mono (3-acryloxypropyl) phosphate) and mono- (methacryloxyalkyl) phosphate.

The amount of acid functional monomer present in the alkyl substituted amine functional polymer will vary depending on the acid used and the method of preparation, but is typically an amount of 15 wt% or less of the acid functional monomer to be used in P1 (based on the weight of the total monomer composition). Preferably, 1 to 10 wt% of the acid functional monomer is used in P1. The neutralized carboxylic acid groups provide stability to the dispersion, but also react with the epoxy. In addition, these groups also catalyze the reaction between epoxy and amine groups. The amount of acid is preferably chosen not too high in view of maintaining good water resistance of the resulting coating. The amount of acid monomer in the polymer dispersion can be at least 2, 3, 6 or even 8 wt% relative to the weight of oligomer P1, and at least 1,3 or even 4 wt% relative to the total weight of P1+ P2.

The amine-functional monomer M2 having a sterically hindered secondary or tertiary amine group used in the second monomer mixture of the process of the invention can be selected from a wide variety of monomers. An advantage of the present invention is that both water soluble and water insoluble amine group containing monomers can be used with good conversion without coagulation. Preferred amine functional monomers M2 are alkyl substituted amine functional ethylenically unsaturated monomers defined by the following structure:

wherein R is hydrogen, alkyl having 1 to 4 carbon atoms or phenyl, A is alkylene having 2 to 10 carbon atoms, and X is oxygen or nitrogen, preferably oxygen. R1 and R2 are each independently alkyl having 1 to 12 carbon atoms, or in the case of a sterically hindered secondary amine, R1 is hydrogen and R2 is a sterically hindered alkyl, especially R2 contains 4 or more carbon atoms, preferably tert-butyl.

Illustrative examples of alkyl substituted amine monomers M2 include dimethylaminoethyl acrylate and methacrylate, diethylaminoethyl acrylate and methacrylate, dimethylaminopropyl acrylate and methacrylate, dipropylaminoethyl acrylate and methacrylate, di-N-butylaminoethyl acrylate and methacrylate, di-sec-butylaminoethyl acrylate and methacrylate, di-tert-butylaminoethyl acrylate and methacrylate, monoamides of diamines of ethylenically unsaturated carboxylic acids, such as N, N-dimethylaminopropyl acrylamide and N, N-dimethylaminopropyl methacrylamide. The most preferred alkyl substituted amine functional ethylenically unsaturated monomers are dimethylaminoethyl methacrylate and p-tert-butyl methacrylate.

A particular advantage of the present invention is that the amount of amine groups and the amount of acid groups in the polymer can be high, thereby improving the coating properties, in particular the bleed-out resistance, without the risk of dispersion stability. In particular, the amount of amine monomer can be at least 5, preferably at least 7, 10, 15, more preferably at least 20 or even higher than 30 wt% with respect to the weight of polymer P2, and at least 5, 8, 10 or even at least 15 wt% with respect to the total weight of oligomer and polymer P1+ P2. The amount of acid + amine monomer in the polymer dispersion can be at least 5, 10, 15 or even at least 20 wt% (relative to P1+ P2).

The amount of amine monomer present in the polymer dispersions of the present invention will vary depending on the amine used and the method of preparation, but typically an amount of 2 wt% or more of the amine functional monomer (based on the total weight of the monomers) will be used. Preferably, 3 to 30 wt% of amine functional monomer, most preferably 5 to 25 wt% of amine functional monomer is used in P2. In a one-component embodiment, i.e., without a reactive co-binder, the amine groups will be protonated by the carboxylic acid groups from the first polymer phase, thereby forming ionic crosslinks. In both the one-component and two-component embodiments, the presence of quaternized or protonated amine groups aids in the adhesion properties of the dried coating film on the substrate. Furthermore, in two-component compositions with polyepoxide co-binders, the amine groups provide crosslinking with the epoxide groups and will be converted to quaternized amine functional groups. This positively charged group will form a complex with extractables in wood (tannins, tree resins) and also provide an antimicrobial function.

The remaining monomer composition consisted of "nonionic" vinyl monomer M3, meaning that the monomer other than monomers M1 and M2 did not contain ionizable groups. In general, it is preferred that the monomer M3 is selected from aliphatic or aromatic saturated or unsaturated vinyl monomers.

Suitable monomers M3 include, but are not limited to, ethylenically unsaturated vinyl monomers such as 1, 3-butadiene, isoprene, divinylbenzene, aromatic vinyl monomers such as styrene, alpha-methylstyrene; vinyl monomers such as acrylonitrile, methacrylonitrile; vinyl halides such as vinyl chloride; vinylidene halides such as vinylidene chloride; vinyl esters such as vinyl acetate, vinyl propionate, vinyl laurate; vinyl esters of versatic acids, e.g. VeoVa^TM9 and VeoVa^TM10(VeoVa is a trademark of Hexion); a heterocyclic vinyl compound; alkyl esters of monoethylenically unsaturated dicarboxylic acids, e.g. di-n-butyl maleate and di-n-butyl fumarate, especially of the formula CH₂＝CR₅-COOR₄Of acrylic acid and methacrylic acid, or of a mixture thereof,wherein R is₅Is H or methyl, R₄Are optionally substituted C1 to C20, more preferably C1 to C8 alkyl, cycloalkyl, aryl or (alkyl) aryl groups, also known as acrylic monomers, examples of which are methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate (all isomers), 2-ethylhexyl (meth) acrylate, isopropyl (meth) acrylate, propyl (meth) acrylate (all isomers), and hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and modified analogs thereof, e.g., TONE M-100(TONE is a trademark of Dow Chemical). Examples of suitable nonionic monomers also include, for example, acrylonitrile, acrylamide, alkyl substituted acrylamide monomers, or mixtures thereof.

Suitable nonionic crosslinkable monomers M3 include allyl (meth) acrylate; acrylic and methacrylic esters of diols, triols, such as ethylene glycol di (meth) acrylate, 1, 3-butanediol di (methacrylate), 1, 6-hexanediol di (meth) acrylate, trimethylolpropane triacrylate; divinylbenzene; dicyclopentadienyl (meth) acrylate; a butadiene monomer; glycidyl (meth) acrylate; acetoacetoxyethyl (meth) acrylate; acrolein, methacrolein; diacetone (meth) acrylamide; isocyanatoethyl methacrylate, dimethyl meta-isopropenyl benzyl isocyanate or various mixtures thereof. Some nonionic crosslinkable monomers that provide crosslinking after the coating film has dried require the addition of an appropriate co-reactant to the anionic dispersion.

Other ethylenically unsaturated monomers M3 which can be used are those containing fatty acid derived ester groups, such as oleyl (meth) acrylate, linoleyl (meth) acrylate and linolenyl (meth) acrylate, the synthesis of which is described in J.appl.Poly.Sci.,30,4571-4582(1985), and similar vinyl esters or monomers are derived from the addition reaction between glycidyl (meth) acrylate and fatty acid, as described in British patent application GB 2237276. These monomers can provide the autoxidative drying properties of the polymer portion of the vinyl copolymer. Other monomers that can be used include vinyl oxazoline diesters of unsaturated fatty acids, such as Dapro FX 521 commercially available from Elementis Specialties.

For the first emulsion polymerization, it is preferred to add an anionic surfactant and optionally further nonionic surfactant, and to carry out the second emulsion polymerization optionally in the presence of nonionic surfactant, which is present in the first step and/or is added before the second step after the first step.

Surfactants that can be used in the emulsion polymerization process are ionic or nonionic surfactants. Non-limiting examples of anionic emulsifiers are: potassium laurate, potassium stearate, potassium oleate, sodium decyl sulfate, sodium dodecyl sulfate, and sodium abietate. Examples of nonionic emulsifiers are: linear and branched alkyl and alkylaryl polyethylene glycol ethers and thioethers and linear and branched alkyl and alkylaryl polypropylene glycol ethers and thioethers, adducts of alkylphenoxy-poly (oxyethylene) ethanols, such as 1 mole of octyl-or nonylphenol, with 5 to 50 moles of ethylene oxide, or alkali metal or ammonium salts of sulfuric or phosphoric acid esters of said adducts. Surfactants containing ethylenically unsaturated groups that can participate in free radical polymerization can also be used. Suitable polymerizable surfactants include those of formula M⁺Half esters of maleic anhydride of-OOC-CH ═ CHCOOR, where R is C6-C22 alkyl, M⁺Is Na⁺,K⁺,Li⁺,NH4⁺Or protonated or quaternary amines. Polyoxyethylene alkylphenyl ethers having ethylenic unsaturation

RN (from DKS Co. Ltd.) sales, e.g. NOIGEN RN-10^TM,NOIGEN RN-20,NOIGEN RN-30,NOIGEN RN-40^TMAnd NOIGEN RN-5065^TMOr its trade name

Sulfates sold by BC (from DKS Co. Ltd.), e.g. HITENOL BC-10^TM,HITENOL BC-1025^TM,HITENOL BC-20^TM,HITENOL BC-2020^TM,HITENOL BC-30^TM。MAXEMUL^TM6106 (available from Croda Industrial Specialties) (nominal C18 alkyl chain with phosphonate and ethoxy hydrophilic, acrylate reactive groups). Other representative reactive surfactants having phosphate functional groups suitable for such reactions include, but are not limited to, MAXEMUL^TM6112,MAXEMUL^TM5011,MAXEMUL^TM5010 (all available from Croda Industrial Specialties). Alternative reactive surfactants suitable for use in various embodiments of the present invention include sodium allyloxy hydroxypropyl sulfonate (available from Solvay-Rhodia as SIPOMER COPS-1)^TMAvailable) of the ADEKA REASOAP SR/ER series, such as ADEKA REASOAP ER-10, ER-20, ER-30 and ER-40, Akeda REASOAP SR-10, SR-20, SR-30 (all available from Asahi Denka Co., Ltd.) and allyl sulfosuccinate derivatives (such as TREM LF-40 available from Cognis)^TM))。

The amount of surfactant used is preferably from 0.1 to 15 wt%, more preferably from 0.1 to 8 wt%, still more preferably from 0.1 to 5 wt%, particularly from 0.1 to 3 wt%, most particularly from 0.3 to 2 wt%, based on the weight of the vinyl copolymer P1+ P2.

The first emulsion polymerization can be carried out starting from a seed emulsion, which can be of the same or different monomer composition as the first stage acidic oligomer P1. If a polymer seed is used in the process, having the same monomer composition as P1, the seed polymer is part of the P1 polymer. If the polymer seed is used with a monomer composition other than P1, for example, having a lower content of acid functional monomer, the seed may form a different phase in the dispersion particles and is not considered part of P1 for any calculation purposes herein.

Free radical emulsion polymerization of vinyl monomers will require the use of free radical generating initiators to initiate vinyl polymerization. Suitable free radical generating initiators include inorganic peroxides such as, for example, persulfate K, Na or ammonium, hydrogen peroxide or percarbonate; organic peroxides, such as acyl peroxides, including, for example, benzoyl peroxide, alkyl hydroperoxides such as tert-butyl hydroperoxide and cumene hydroperoxide; dialkyl peroxides, such as di-tert-butyl peroxide; peroxyesters such as t-butyl perbenzoate and the like; mixtures may also be used.

In some cases, the peroxy compound is advantageously used in combination with a suitable reducing agent (redox system) such as Na or K metabisulfite or Na or K bisulfite, sodium formaldehyde sulfoxylate, disodium 2-hydroxy-2-sulfinato acetate and erythorbic acid. Metal compounds such as Fe. Ethylenediaminetetraacetic acid (EDTA) may also be used as part of the redox initiator system. Azo-functional initiators may also be used. Preferred azo initiators include azobisisobutyronitrile, 2,2' -azo-bis (2-methylbutyronitrile) (ANBN); and 4,4' -azobis (4-cyanovaleric acid). Initiators that partition between the aqueous and organic phases may be used, such as a combination of t-butyl hydroperoxide, erythorbic acid, and fe. The amount of initiator or initiator system used is conventional, for example in the range of from 0.05 to 6% by weight, based on the total vinyl monomers used.

The polymerization of P2 can be carried out by any method known to those skilled in the art, such as core/shell, gradient morphology, and the like. The amine-functionalized polymer dispersions of the present invention may be prepared according to any of a number of emulsion polymerization processes. For a general description of the Emulsion polymerization process, we refer to "Chemistry and Technology of Emulsion polymerization", edited: van Herk, Blackwell Publishing Ltd, 2005.

Molecular weight control of the copolymers P1 and P2 can be provided by the use of chain transfer agents. In particular, the first emulsion polymerization is preferably carried out in the presence of a chain transfer agent in order to obtain the copolymer P1 of lower molecular weight. Suitable chain transfer agents are mercaptans and halogenated hydrocarbons. Alternatively, catalytic chain transfer agents such as cobalt-chelates can be used, for example those used in N.S. Enikolopyan et al, J.Polym.chem.Ed, Vol 19,879 (1981). It is also possible to use alpha-methylstyrene dimers or oligomers of alpha-methylstyrene dimers, as explained in US 2007/0043156 a1 and US 6,872,789. Another method of synthesizing polymers with well-defined molecular weights is to use diarylethenes. The use of diarylethenes is described in detail in W.Bremser et al, prog.org.coatings,45, (2002),95 and JP 3135151, DE 10029802 and US 2002/0013414. Commonly used diarylethenes include stilbene. Suitable chain transfer agents include mercaptans such as n-dodecyl mercaptan, n-octyl mercaptan, t-dodecyl mercaptan, mercaptoethanol, isooctyl thioglycolate, C2-C8 mercaptocarboxylic acids and esters thereof such as 3-mercaptopropionic acid and 2-mercaptopropionic acid; and halogenated hydrocarbons such as carbon tetrabromide and bromotrichloromethane. Thiols are preferred.

According to the present invention, a novel aqueous anionically stabilized polymer dispersion is provided which has a particularly high content of amine groups and has good dispersion stability and good coating properties. The present invention therefore also relates to an aqueous anionically stabilized polymer dispersion comprising dispersed particles having two or more separate phases within the particles, one phase comprising an acid functional oligomer substantially free of amine functional monomers and another separate phase comprising an amine functional polymer substantially free of acid functional monomers, and wherein the amount of amine functional monomers is at least 4 wt% relative to the total weight of polymers or oligomers in the dispersed particles.

In particular, the present invention relates to an aqueous anionic polymer dispersion obtainable by the above process, more particularly to an aqueous anionic polymer dispersion comprising dispersed particles having a first phase and a second phase separated within said particles, wherein

a. The first phase P1 comprises an acid-functional oligomer comprising acid-functional monomers and comprising less than 2 wt.% (relative to the total weight of the acid-functional oligomer), preferably essentially no amine-functional monomers and a number average molecular weight Mn_P1500 to 50000 g/mol, preferably 1000 and 30000 g/mol (determined by GPC using THF or THF in combination with acetic acid) and a Fox glass transition temperature Tg_P1At least 0, preferably 10, more preferably 15, most preferably at least 20 ℃, and wherein

b. The second phase P2 comprises an amine-functional polymer comprising sterically hindered secondary or tertiary amine groups amine-functional monomer M2 and less than 2 wt.% (relative to the total weight of the second monomer mixture), preferably essentially free of acid-functional monomers and having a number average molecular weight Mn_P1Usually 1000 to 1000000 g/mol, preferably 10000 and 800000 g/molAnd Fox glass transition temperature Tg_P2At least 0 c,

c. the dispersion has a pH in the range of 6 to 11, preferably 7.5 to 11,

d. wherein Tg is_P2Specific Tg_P1At least 5 c, more preferably at least 7, 10 or 20 c,

e. among them, Mn is preferred_P2Specific Mn_P1Highly preferably at least 1000 g/mol, more preferably at least 2000, 4000 or 8000 g/mol, and

f. among them, preferred is_TP1And_TP2the difference is at least 0.1, preferably at least 0.2, wherein_TP1And_TP2is the Hoy solubility parameter of the first phase (P1) and the second phase (P2),

wherein two Fox Tg's were calculated as the Hoy parameters based on the constituent monomers in P1 and P2 without including a chain transfer agent or a reactive surfactant.

In the aqueous anionic polymer dispersions of the present invention or aqueous coating compositions prepared therefrom, substantially all amine groups in the polymer dispersion are maintained in a deprotonated state by ensuring that the pH of the composition is in the range of from 6 to 11, preferably from 7.5 to 11.0, more preferably from 8.5 to 10.5. Deprotonation of the amine functional groups helps to maintain colloidal stability of the composition.

The aqueous anionically stabilized polymer dispersions of the invention are suitable for use in coating compositions as binders. The aqueous anionically stabilized polymer dispersion in alternative a) does not contain a substantial amount of co-binder, or in alternative B) also contains a co-binder B that does not react with the acid groups of the acid functional oligomer or with the amine groups on the amine functional polymer, or in alternative C) further contains a reactive co-binder C that reacts with the acid groups of the acid functional oligomer or with the amine groups on the amine functional polymer binder or both, or in alternative D) further contains both co-binders B and C. By insignificant amounts herein is meant less than 5, preferably 3 or 1, most preferably 0 wt% of the sum of the anionic polymeric binder and the co-binder. The reactive co-binder C is preferably selected from water-soluble or water-dispersible polyepoxides.

In the coating composition according to alternative a, the anionic polymer dispersion is used as the sole binder, i.e. without co-binder, but it may contain the usual coating additives as described below. The coating composition according to alternative B may be in the form of a one-component system comprising an anionic polymer dispersion mixed with a solution or aqueous dispersion of a non-reactive co-binder B. In this case, the composition does not contain a co-binder which reacts with the amine or acid groups of the copolymer P1 or P2.

The aqueous anionically stabilized polymer dispersion according to alternative C is preferably in the form of a two-component system comprising 2 or more parts, wherein one part comprises the anionically stabilized polymer dispersion, the other part comprises an aqueous solution or dispersion of the reactive co-binder C and/or an aqueous solution or dispersion of a separate crosslinking agent and one or both parts optionally comprise the non-reactive co-binder B.

More preferably, the coating composition according to alternative C is in the form of a two-component system comprising 2 or more parts (kit of parts), wherein one part comprises the anionically stabilized polymer dispersion, the other part comprises the dispersion of the reactive co-binder C, and one or both parts optionally further comprise the non-reactive co-binder B. In the latter case, the anionically stabilized polymer dispersion is preferably blended with an aqueous dispersion of the reactive co-binder prior to application of the coating. After mixing the two components, the anionically stabilized polymer and the reactive co-binder are present in the aqueous dispersion as separate particles. In this embodiment, the reaction with the reactive co-binder is at least delayed by separating the reactive components in the different particles. It is important to control the size of the different individual particles in alternative C. More preferably, the size ratio of the different individual particles is designed to avoid particle stratification during film formation. In the particular case where one of the particle populations migrates to the surface or bottom of the membrane, the reactivity of the two components may be compromised. More preferably, the size ratios of the different individual particles are designed to allow the population of particles to react immediately by their respective coalescence and interdiffusion.

The non-reactive co-binder is preferably selected from the group consisting of non-reactive aqueous vinyl dispersions, water soluble vinyl polymers or oligomers, water reducible alkyd and polyester resins, alkyd emulsions that dry by autoxidation, polyester emulsions, polyurethane dispersions, fatty acid modified polyurethane dispersions, polyurethane-acrylic urethane hybrid polymer dispersions, alkyd-acrylic hybrid polymer dispersions, preferably without substantial amounts of reactive co-binder.

The aqueous coating composition of the present invention may optionally contain coating ingredients including, but not limited to: pigments such as titanium dioxide or carbon black; extenders such as calcium carbonate, talc, clay, silica and silicates; fillers such as glass or polymer microspheres, quartz and sand; a thickener; a rheology modifier; a dye; a chelating agent; a biocide; a dispersant; an anti-freezing agent; a plasticizer; an adhesion promoter; a coalescing agent; a wetting agent; a wax; a surfactant; a slip-aid additive; a crosslinking agent; defoaming agents; a colorant; a preservative; freeze/thaw protectants and corrosion inhibitors.

Other optional coating additives include, but are not limited to: co-solvents, reactive pigments, UV absorbers, antioxidants and stabilizers. These optional components (as desired) may be added in any order of addition that does not result in incompatibility between the components. Components that are insoluble in the aqueous carrier (e.g., pigments and fillers) can be dispersed in the polymer dispersion or the aqueous carrier or co-solvent using a high shear mixer. An advantage of the present invention is that commonly available coating additives and components can be used.

In embodiment C, it is advantageous to formulate the coating composition in the presence of the anionically stabilized polymer dispersion and add the co-reactive polymer dispersion prior to application of the coating.

The aqueous coating compositions of the present invention can be used to provide coatings on suitable substrates, such as wood and recycled wood products, cementitious substrates such as concrete or fiber cement, asphalt, stone, marble, clay, plastics, paper, cardboard and metals (ferrous and non-ferrous). The fast drying nature of these compositions makes them particularly suitable for use in road marking coatings and maintenance coatings for substrates where rapid development of water resistance is important.

The aqueous coating composition of the present invention can be applied to a desired substrate using conventional coating techniques such as conventional or airless spraying, roll coating, brush coating, curtain coating, flood coating, and dip coating. Once applied to a substrate, the coating compositions of the present invention are typically cured at ambient temperature, or in some cases at elevated temperature, depending on the substrate used.

In one embodiment of the coating composition, the anionically stabilized amine functional polymer dispersion is combined with a second component having functional groups that are co-reactive with an amine or carboxylic acid. This second co-reactive component may be a reactive polymeric co-binder (alternative C), but may also be a low molecular weight compound or a separate compound that merely provides the dispersed polymer with quaternized or protonated amine groups. This embodiment serves as a so-called two-component system, adding a co-reactive second component to the anionic alkyl-substituted amine functional polymer dispersion just prior to application to the substrate. It is noted that the pH of the blend is within the above range. Optionally, a catalyst is added to the mixture to control the reaction rate.

Preferred co-reactive functional groups are epoxy groups:

wherein R is any group capable of linking an epoxy group to a backbone bearing at least one other epoxy group. The backbone can be a polymer, such as an addition, polycondensation or polyaddition polymer. The polyepoxy-functional polymer dispersion can be synthesized directly in water, for example by the emulsion polymerization method described above using ethylenically unsaturated monomers having epoxy functionality, or can be synthesized using conventional methods and then emulsified in water. Thus, it is preferred that the coating composition comprises a co-reactant selected from polyepoxides. The polyepoxides used in the present invention can be water-soluble or water-dispersible polyfunctional epoxy-containing materials, prepolymers or polymers or mixtures thereof, provided that they are compatible with the anionic dispersions of the present invention.

Non-limiting examples of water-soluble polyepoxides are glycidyl ethers of polyhydric alcohols, such as 1, 4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, sorbitol polyglycidyl ether, and the like. The polyepoxides dispersed in water can be prepared by emulsion polymerization using glycidyl methacrylate as the epoxy functional comonomer.

Methods for synthesizing epoxy-functional acrylic dispersions are given, for example, in GB 2,206,591B or WO 01/74930. Epoxy functional polymer dispersions are also commercially available from Allnex Netherlands BV under the tradenames Setaqua 8550, Setaqua 8554, and Setaqua 8555.

Epoxy resins consisting of the reaction product of bisphenol a or bisphenol F with epichlorohydrin can also be emulsified in water using external or internal surfactants. Commercially available products are for example available from Hexion as EPI-REZ^TMEpoxy Waterborn Resins or by Allnex under the trade name

EP is provided.

When the functional groups of the anionic amine functional polymer dispersion react with the epoxy groups from the aqueous coreactive polymer dispersion or emulsion, crosslinking of the polymer occurs due to the following reaction:

the reaction between the epoxy functional groups and the alkyl-substituted amine functional groups results in the formation of quaternized amine crosslinks, thereby imparting cationic functionality to the coating film. The presence of quaternized amine functional groups in the dried coating can be beneficial because it can impart certain properties to the coating, such as preventing migration of acidic species from the substrate through the coating, such as wood and knot (knot) forming extractable species such as tannins and resins, or antimicrobial properties. Another reaction that may occur is the reaction between the carboxylic acid groups present in the anionically stabilized amine functional dispersion and the epoxy groups of the co-reactant. Thus, the coating compositions are particularly useful in coating compositions and coatings that provide bleed-out resistance or antimicrobial properties. For this purpose, the coating compositions usually comprise an anti-bleeding additive, in particular zinc oxide. The coating composition of the invention has inherent anti-bleed properties and therefore requires less or no anti-bleed additive, in particular an amount of less than 50% of the envisaged amount, preferably substantially no anti-bleed additive, preferably less than 5, 4, 3 or even less than 1 wt%, relative to the total weight of the coating composition.

The present invention also relates to a cured coating having improved bleed-out or antimicrobial properties comprising the cured coating composition of the present invention; preferably with low or no bleed-out resistance additives, including quaternized or protonated amine groups, preferably quaternary ammonium salt groups, resulting from the reaction of the amine groups of the anionic polymer with the epoxy groups of the reactive co-binder. Furthermore, the present invention relates to the use of the aqueous anionically stabilized polymer dispersions according to the invention for producing coating compositions for producing coatings having bleed-out resistance or antimicrobial properties.

Detailed Description

The invention is further illustrated by the following examples:

monomers used

Other materials used

The test method used was:

determination of molecular weight

Molecular weight and molecular weight distribution were determined using size exclusion chromatography. The size exclusion device used was an Alliance system consisting of a pump, autosampler and He-degasser (Degasys DG-1210 from Uniflows) equipped with a PLgel 5 μm MIXED-C600 x7.5mm column and a Pgel 5 μm guard column (50x7.5mm-Polymer Laboratories). The column oven (Separations Analytical Instruments) was set at 30 ℃. Tetrahydrofuran (THF-Extra Dry, Biosolve 206347) + 2% acetic acid (Baker 6052) was used as eluent at a flow rate of 0.8 ml/min. Carbon disulfide (baker) was used as the marker. The Waters 410 refractive index serves as the detector. The injection volume was 100. mu.l, the concentration was 1.5 mg/ml. Polystyrene standards (Polymer Laboratories, Easical PS-1,2010-0501(M range 580 g/mol-8500000 g/mol) and Easical PS-2,2010-0601(M range 580 g/mol-400000 g/mol)) were used for calibration using a third order polynomial. The software used for data analysis was empower (waters).

Determination of minimum film Forming temperature (MFT)

The minimum film-forming temperature (MFT) was determined by using Rhopoint MFFT-Bar 60, which ranged from 0 ℃ to 60 ℃. The wet film thickness of the applied film was 25 microns. The MFT is the lowest temperature at which the film is crack free.

Measurement of particle diameter

Particle size was determined by dynamic light scattering using a Malvern Zetasizer model Nano-S90. The Z-average is reported as the particle size. The Z-average diameter is the mean hydrodynamic diameter and is calculated according to the International Standard for dynamic light Scattering ISO 13321.

Determination of pH

The pH was measured using a Proline QIS pH meter.

Measurement of Koenig hardness

After applying a 100 μm wet film on glass and drying the film at 23 ℃/45% RH for 7 days, the Koenig hardness according to ASTM D4366 was measured.

Determination of coffee resistance

Coffee resistance was evaluated as follows: in that

A125 μm wet film was applied to the card. The membrane was dried at 23 ℃ at a relative humidity of 45% for 24 hours and then oven dried at 50 ℃ for 16 hours. Use of

Powdered coffee (4 grams) and boiling water (100 grams) to prepare the coffee solution. Cooling the coffee solution to room temperature and then applying droplets onto the square cut filler; then is at

The dried paint film of the white portion of the card was covered with a crystal. The coffee speckles are then removed after a selected time, and the stain is wiped off with a wet cloth to remove any residual coffee. The remaining traces were then visually judged and ranked according to their severity, from 5 (no visible stain) to 1 (very visible coffee stain).

Determination of Water resistance

The water resistance was evaluated as follows: applying demineralized water to

On the card, the card was prepared in the same manner as described for the coffee test. Water was removed after the desired test time and the test points were allowed to recover for 1 hour before visual judgment. A rating of 5-1 is given according to the severity of the mark left on the film surface. 5-no visible marks to 1-severe surface damage.

Example 1.A preparation of a first stage aqueous anionically stabilized polymer dispersion.

1253.0g of demineralized water were added to a 3.5 liter reactor, followed by 7.8g of surfactant 1; it was mixed and heated to 80 ℃ under nitrogen atmosphere. Monomer emulsions having the compositions in table 1 were prepared in parallel. When the desired temperature was reached, 105g of the monomer emulsion was added to the reactor together with 0.2g of APS in 10.0g of demineralized water. The remaining monomer emulsion and a solution of 7.8g APS and 358.1g demineralized water were added to the reactor at 180 minutes and 200 minutes (85 ℃ C.) respectively. After the feeding process, the reactor was maintained for 60 minutes, and then 25 wt% aqueous ammonia solution was added to increase the pHTo a value of 8. The dispersion had a solids content of 26% and a particle size of 28 nm. M by GPC_nAnd a calculated Tg of 17286 g/mole and 19 ℃ based on the Fox of the polymer, respectively. The calculated solubility parameter T was 19.43 (J/m)³)^1/2

Table 1:

components	Quantity (g)
		Softened water	295.50
Surfactant 2	42.1
		MMA	402.1
n-BA	358.1
		MAA	67.2
OM	8.6
		ME	4.3

B preparation of a second stage anionically stabilized amine functional polymer dispersion.

A3.5 liter reactor was charged with 841.3g of the first stage aqueous anionic polymer dispersion of example 1.A and heated to 70 ℃ under a nitrogen atmosphere. After reaching the required temperature; an aqueous solution of TBHP (1.5g in 12.4g demineralized water) and 0.62g surfactant 3 were added to the reactor. A monomer mixture having the composition described in table 2 was added to the reactor over 100 minutes. In parallel, an aqueous reducing agent solution consisting of 1.04g of FF6 and 124.4g of demineralized water was added over 120 minutes. The reactor was cooled to 60 ℃ and then a lance of 1.1 wt% demineralized water and 47.1 wt% of an aqueous solution of TBHP and reducing agent (based on initial addition at 70 ℃) were added. The reactor was cooled to 40 ℃ and a solution of 4.5g of biocide solution (PAQ) and 6.0 demineralized water was added. The dispersion had a solids content of 37%, a particle size of 244nm, 3.5% by weight of acid-functional monomers and 12.3% by weight of amine-functional monomers (on solid polymer P1+ P2).

The difference in number average molecular weight Δ Mn between the first and second stage polymers_1B-1AThe difference in glass transition temperature Δ Tg between the first and second stage polymers, determined as 2418 g/mol, was calculated according to equation Fox_1B-1AAt 19 ℃ the difference in the calculated solubility parameters between the first and second stage polymers, Δ_1B-1AIs 0.38 (J/m)³)^1/2。

Table 2:

components	Weight (g)
		MMA	62.2
n-BA	124.4
		STY	37.3
DMAEMA	62.19

Examples 2 to 4: other anionically stabilized amine functional polymer dispersions were prepared.

Using the starting materials in table 3, an additional two-stage acid/amine functional dispersion was prepared using the method described in example 1B.

Table 3.

The properties of the resulting polymer dispersion are listed in table 4. The difference between the Tg's of the first and second stage polymers is equal to 19 ℃ for all samples and the difference in the calculated solubility parameter, Δ_TIs 0.29 (J/m)³)^1/2。

TABLE 4 Properties of anionically stabilized amine functional polymer dispersions.

Comparative example 5: preparation of a one-stage anionically stabilized amine-functional Polymer Dispersion according to US5,709,714 example 8 A body comprising DMAEMA.

589.2g of demineralized water and then 7.8g of surfactant 1 are added to a 3.5 liter reactor; it was mixed and heated to 80 ℃ under nitrogen atmosphere. Monomer emulsions having the compositions given in table 5 were prepared in parallel. When the desired temperature was reached, 33.4g of MMA and 8.4g n-BA were added to the reactor together with 1.2g of APS dissolved in 10.0g of demineralized water. The system was allowed to react for 15 minutes. After this seed stage, the monomer emulsion and a solution of 3.0g APS, 5.9g sodium bicarbonate and 294.6g demineralized water were added to the reactor at 180 minutes and 200 minutes (85 deg.C), respectively. After the feed process, the reactor was held for 60 minutes, then an ammonia solution (10.3g of 25 wt% ammonia +106g of demineralized water) was added. The reactor was cooled to 40 ℃ and a solution of 4.5g PAQ and 5.0 water was added. The solids content of the dispersion was 25-28% (the remaining solids remained as coagulum in a 60 μm filter) and the particle size was 1300-1500 nm.

Table 5:

example 6: a second stage anionically stabilized alkyl-substituted amine-functional polymer dispersion is prepared. Of amine concentration Influence.

To a 70mL microreactor (in series) was added 59.05g of the first stage aqueous anionic polymer dispersion of example 1.A and heated to 70 ℃ under a nitrogen atmosphere. After reaching the required temperature; to the reactor was added an aqueous solution of TBHP (0.05g +0.08g demineralized water) and 0.02g of surfactant 3 dissolved in 0.08g demineralized water. The monomer mixture (each for each reactor 1-4) having the composition described in table 6 was added over 100 minutes. In parallel, an aqueous solution of reducing agent (0.04g FF6+0.16g demineralized water) was added over 120 minutes. The reactor was cooled to 60 ℃ and then a gun of 95.5 wt.% and 100.0 wt.% of TBHP and aqueous reducing agent solution (based on the initial addition at 70 ℃) were added. The reactor was cooled to 40 ℃ and the dispersion was filtered through 60 μm. The characteristics of the dispersions are presented in table 6.

Table 6:

these examples show that high concentrations of amino-functional monomers can be copolymerized in the compositions according to the invention.

Comparative example 7: preparation of anionically stabilized amine functional polymer dispersions by blending

In a first step, an amino-functional single-stage dispersion free of carboxylic acid groups was prepared as follows: 747.0g of demineralized water were added to a 3.5 liter reactor, followed by 1.5g of surfactant 3; it was mixed and heated to 80 ℃ under nitrogen atmosphere. Monomer emulsions having the compositions given in table 7 were prepared in parallel. When the desired temperature was reached, 5 wt% of the monomer emulsion was added to the reactor along with 0.8g APS in 5.0g demineralized water. The remaining monomer emulsion and a solution of 5.6g APS, 5.05g sodium bicarbonate and 80.0g demineralized water were added to the reactor at 120 minutes and 150 minutes (80 ℃ C.) respectively. After the feed process, the reactor was held at 85 ℃ for 60 minutes. The dispersion had a solids content of 35%, a particle size of 217nm and a pH of 8.7.

Table 7:

components	Quantity (g)
		Softened water	232.8
Surfactant 2	30.8
		MMA	331.3
n-BA	142.0
		STY	47.4
DMAEMA	94.7

The aqueous amino-functional dispersion thus obtained was blended with the aqueous anionic polymer dispersion of example 1A in different proportions with stirring. The characteristics of these dispersions are described in table 8.

Table 8:

from these results, it is clear that it is advantageous to prepare P2 in the presence of P1.

Example 8: epoxy functionalized dispersions were prepared.

632.3g of demineralized water were added to a 3.5 liter reactor, followed by 0.42g of surfactant 1; it was mixed under nitrogen atmosphere and heated to 72 ℃. Monomer emulsions having the compositions given in table 9 were prepared in parallel. When the desired temperature was reached, a 5 wt% monomer emulsion was added to the reactor along with 26.1g of TBHP dissolved in 35.8g of demineralized water. Thereafter, a gun (0.86g FF6+28.6g demineralized water) of an aqueous reducing agent solution was added. The system was allowed to react for 30 minutes. The remaining monomer emulsion and the parallel aqueous reducing agent solution (5.9g FF6+128.2g demineralized water) were fed in 180 minutes and 195 minutes, respectively. The reactor contents were cooled to 65 ℃ and then 1.7TBHP and aqueous reducing agent (1.8g FF6+15g demineralized water) were added. The reactor was held at 85 ℃ for 30 minutes. The dispersion had a solids content of 50-52%, a particle size of 245nm and a pH of 8.1.

Table 9:

components	Quantity (g)
		Softened water	554.5
Surfactant 3	61.6
		MMA	540.8
n-BA	505.8
		OM	4.2
ME	30.7
		Glycidyl methacrylate	359.0

Example 11: and (5) testing application performance.

The dispersions of examples 2-4 and 6a-6d were formulated into clear coats by adding 4 wt% butyl diglycol with continuous stirring to improve film formation. The formulations were applied and evaluated as described above. The test results are presented in table 10.

Table 10:

this experiment shows that the composition according to the invention forms a glossy uniform film with good water and stain resistance.

Examples 12 to 17: two-component pigmented coating materials.

Pigmented two-component coatings were prepared using the components given in table 11. First, a millbase is prepared by high-shear mixing until a fineness of less than 10 μm is obtained. During the Let-down phase, an anionically stabilized amine functional dispersion and butyl diglycol are added. This is component a of the coating. Before application, component B is added to component a with stirring.

Table 11:

pigment dispersants from Byk Chemie

Titanium dioxide from Kronos inc

Antifoam from Byk Chemie

Epoxy functional acrylic dispersions from Allnex Netherlands b.v.

The coating composition was applied as described above, cured and evaluated. The results are given in table 12.

Table 12:

examples 18 to 22: other anionically stabilized amine functional polymer dispersions were prepared. Thiol and amine functional monomers plus The impact of the mode.

Using the starting materials in table 13, additional two-stage acid/amine functional dispersions were prepared using the method described in example 1B.

Watch 13

(60 minutes after pre-emulsification feed, 90% of the total DMAEMA was added as neat feed, both feeds were added at the same feed rate)

TABLE 14 Properties of anionically stabilized amine functional polymer dispersions.

The properties of the resulting polymer dispersion are listed in table 14. The difference between the Tg's of the first and second stage polymers was about 18-20 ℃ for all samples and the difference in the calculated solubility parameters, Δ_TIs 0.29 (J/m)³)^1/2。

Examples 23 to 24: other anionically stabilized amine functional polymer dispersions were prepared. Effect of DMEA neutralization.

Using the starting materials in table 15, additional two-stage acid/amine functional dispersions were prepared using the method described in example 1B. In the following examples, polymer P1 was neutralized using DMEA instead of ammonia.

Table 15:

Table 16. The nature of the anionically stabilized amine functional polymer dispersion.

The properties of the resulting polymer dispersion are listed in table 16. The difference between the Tg's of the first and second stage polymers was about 18-20 ℃ for all samples and the difference in the calculated solubility parameters, Δ_TIs 0.29 (J/m)³)^1/2。

Examples 25 to 27: other anionically stabilized amine functional polymer dispersions were prepared. Effect of P1 concentration.

Using the starting materials in table 17, an additional two-stage acid/amine functional dispersion was prepared using the method described in example 1B.

Table 17:

Table 18. Properties of the anionic amine functional polymer dispersion.

The properties of the resulting polymer dispersion are listed in table 18. The difference between the Tg's of the first and second stage polymers was about 18-22 deg.C for all samples and the calculated difference in solubility parameter, Δ_TIs 0.30 (J/m)³)^1/2。

Examples 28 to 37: knot-bleeding performance test.

The pine board with knots is coated by dipping the board into a coating. Dried vertically for 15 minutes and then at room temperature for 16 hours. Thereafter, the panels were coated with a topcoat based on Setaqua 6785 available from Allnex Netherlands B.V. 250 grams per square meter of coating was applied by brush. Drying was carried out by flash evaporation for 1 hour, followed by drying at 50 ℃ for 16 hours. The plate was then placed in a QUV with UV-A radiation. And (3) circulation: 4 hours 60 ℃ UV-A, 4 hours 40 ℃ condensation. The panels were periodically checked for node bleed.

TABLE 19 paint formulation.

Table 19 shows the coating formulations for the process for coating pine boards. Table 20 shows the results regarding the knot bleed performance. Pine boards were visually evaluated to assess the ooze from the knots. The evaluation period was stopped when the knots present in the panel showed significant bleeding. It can be noted that the dispersions developed can be used as primer coatings to reduce the occurrence of knot bleed.

Table 20:

Claims

1.a method of preparing an aqueous anionically stabilized polymer dispersion comprising the steps of:

a. a first emulsion polymerization of a first monomer mixture comprising an acid functional monomer M1 containing acid groups and less than 2 wt.%, relative to the total weight of the first monomer mixture, of an amine functional monomer M2 containing amine groups to form a first phase polymer dispersion of an acid functional oligomer P1, the acid functional oligomer P1 having a number average molecular weight Mn of 500-50,000 g/mole as determined by GPC using THF in combination with acetic acid_P1And a Fox glass transition temperature Tg of at least 0 DEG C_P1，

b. Adding a base to raise the pH to a range of 6-11,

c. in the above-mentionedA second emulsion polymerization of a second monomer mixture comprising an amine-functional monomer M2 with sterically hindered secondary or tertiary amine groups and less than 2 wt% of an acid-functional monomer M1 relative to the total weight of the second monomer mixture in the presence of the first phase polymer dispersion P1 to form a polymer having a Fox glass transition temperature Tg of at least 0 ℃_P2A second phase of amine functional polymer P2,

d. wherein TgP2 is at least 5 ℃ lower than TgP1, and

2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,_TP1and_TP2by at least 0.1, wherein_TP1And_TP2is the Hoy solubility parameter for phases P1 and P2, where the Hoy solubility parameter is calculated based on the constituent monomers in the monomer mixture excluding chain transfer agent or reactive surfactant.

3. The process as claimed in claim 1 or 2, wherein the amine-functional polymer P2 has a number-average molecular weight Mn of 1,000-1,000,000_P2And wherein Mn_P2Higher than Mn_P1。

4. The method of claim 1 or 2, wherein the first monomer mixture comprises:

a.1 to 20% by weight of an acid-functional monomer M1,

b. less than 1 wt% of amine functional monomer M2,

from 80 to 99% by weight of monomers M3 which are different from acid-functional monomers and amine-functional monomers;

and wherein the second monomer mixture comprises:

d.2-45 wt% of an amine functional monomer M2 having a sterically hindered secondary or tertiary amine group,

e. less than 1 wt% of an acid functional monomer M1,

55 to 98 wt% of monomers M3 different from acid-functional monomers and amine-functional monomers;

wherein the wt% is relative to the total weight of the first and second monomer mixtures, respectively,

wherein the amount of the second monomer mixture expressed in wt% is 20-80 wt% with respect to the sum of the first and second monomer mixtures, and

wherein the monomer M3 is a monomer substantially free of ionizable groups.

5. The process according to claim 1 or 2, wherein for the first emulsion polymerization, anionic surfactant and optionally further nonionic surfactant are added, and optionally the second emulsion polymerization is carried out in the presence of nonionic surfactant, which is present from the first step and/or is added after the first step and before the second step.

6. The process according to claim 1 or 2, wherein the amine functional monomer M2 having a sterically hindered secondary or tertiary amine group is an alkyl substituted amine functional ethylenically unsaturated monomer defined by formula I:

wherein R is hydrogen, alkyl having 1 to 4 carbon atoms or phenyl, A is alkylene having 2 to 10 carbon atoms, R₁And R₂Each independently is an alkyl group having 1 to 12 carbon atoms, and in the case of a sterically hindered secondary amine, R₁Is hydrogen and R₂Is a sterically hindered group containing 4 or more carbon atoms, and X is oxygen or nitrogen.

7. An aqueous anionically stabilized polymer dispersion comprising: dispersed particles having separate first and second phases within the particle, wherein

a. The first phase comprises an acid functional oligomer P1, the acid functional oligomer P1 comprising an acid functional monomer and comprising less than 2 wt% of an amine functional monomer M2 relative to the total weight of the acid functional oligomer and having a number average molecular weight Mn determined by GPC using THF in combination with acetic acid of 500 to 50,000 g/mole_P1And a Fox glass transition temperature Tg of at least 0 DEG C_P1And wherein

b. The second phase comprises an amine functional polymer P2, the amine functional polymer P2 comprising an amine functional monomer M2 with sterically hindered secondary or tertiary amine groups and less than 2 wt% of an acid functional monomer M1 relative to the total weight of the second monomer mixture and having a Fox glass transition temperature Tg of at least 0 ℃_P2，

c. The dispersion has a pH in the range of 6 to 11,

d. wherein Tg is_P2Specific Tg_P1At least 5 ℃ lower, and

e._TP1and_TP2by at least 0.1, wherein_TP1And_TP2is the Hoy solubility parameter of the first phase and the second phase, wherein the two Fox tgs as the Hoy solubility parameter are calculated based on the constituent monomers in the monomer mixture excluding chain transfer agents or reactive surfactants.

8. The aqueous anionically stabilized polymer dispersion according to claim 7, wherein the amount of amine functional monomer is at least 4 wt% relative to the total weight of polymer or oligomer in the dispersed particles.

9. The aqueous anionically stabilized polymer dispersion according to claim 7 or 8, which in alternative a) comprises an insignificant amount of co-binder, or in alternative B) further comprises a co-binder B which is not reactive with the acid groups of the acid functional oligomer or with the amine groups on the amine functional polymer, or in alternative C) further comprises a reactive co-binder C which is reactive with the acid groups of the acid functional oligomer or with the amine groups on the amine functional polymer binder or with both, or in alternative D) further comprises both co-binders B and C, wherein an insignificant amount refers to less than 5 wt% of the sum of anionic polymer binder and co-binder.

10. The aqueous anionically stabilized polymer dispersion according to claim 9, in the form of a one-component system comprising the anionically stabilized polymer dispersion blended with an aqueous dispersion or solution of a non-reactive co-binder according to alternative B), or in the form of a two-component system comprising 2 or more parts, wherein one part comprises the anionically stabilized polymer dispersion and the other part comprises an aqueous solution or dispersion of the reactive co-binder C and/or an aqueous solution or dispersion of a separate crosslinker, and one or both parts optionally comprise a non-reactive co-binder B, according to alternative C).

11. The aqueous anionically stabilized polymer dispersion of claim 9, wherein the reactive co-binder C is selected from water-soluble or dispersible polyepoxides.

12. The aqueous anionically stabilized polymer dispersion of claim 10, wherein the reactive co-binder C is selected from water-soluble or dispersible polyepoxides.

13. Use of an aqueous anionically stabilized polymer dispersion according to any of claims 7 to 12 for preparing a coating composition.

14. Use of the aqueous anionically stabilized polymer dispersion according to any of claims 7 to 12 for producing coatings with bleed-out resistance.

15. A coating composition comprising the aqueous anionically stabilized polymer dispersion according to any one of claims 7 to 12 and further coating additives.

16. A cured coating comprising an aqueous anionically stabilized polymer dispersion according to any of claims 7 to 12, which comprises quaternized or protonated amine groups.